A footwear sole incorporating a turntable to minimise injuries of the type just discussed is disclosed in International patent applications PCT/AU91/00590 and PCT/AU94/00002 ("the earlier applications"), the disclosure of which is hereby incorporated by reference. The present invention relates to further developments of, and/or variations of, the general concepts disclosed in these earlier applications.
In the earlier applications a turn table of a generally circular shape is incorporated into a recess in the sole and is capable of rotation through a limited angular extent as defined by a series of interengaging projections and recesses between the turntable and the structure of the sole. The actual effect of the turntable in practice is to allow the sole to pivot about the turnable if the foot is turned or twisted when the turntable is in contact with the ground. The turntable is also subject to a resilient bias which has the effect of returning it to its initial position relative to the sole when the sole is lifted from the ground. The resilient bias may be applied by integral elastomeric projections extending from the turntable as disclosed in application PCT/AU91/00590, or by means of a coil spring assembly incorporated between the underside of the turntable and the sole as described in application PCT/AU94/00002.